9693 lint flow (Agoric#9726)

closes: Agoric#9692, Agoric#9693

## Description

Sets up a convention for `flows` modules and document in the orchestration README. 

Also makes lint config to test them. The lint config is exported as a shared config that developers can use. I've included it in the same PR to make sure it works with the new convention.

### Security Considerations
none

### Scaling Considerations
none

### Documentation Considerations
Documented the convention in the README. I expect it'll make its way to docs.agoric.com as needed.

### Testing Considerations
nothing special

### Upgrade Considerations
not yet deployed

packages/async-flow/package.json

@@ -61,6 +61,6 @@
     "workerThreads": false
   },
   "typeCoverage": {
-    "atLeast": 76.94
+    "atLeast": 77.01
   }
 }

packages/async-flow/src/types.d.ts

@@ -31,7 +31,9 @@ export type GuestAsyncFunc = (
   ...activationArgs: Guest[]
 ) => Guest<Promise<any>>;
 
-export type HostAsyncFuncWrapper = (...activationArgs: Host[]) => HostVow;
+export type HostAsyncFuncWrapper = (
+  ...activationArgs: Host<any>[]
+) => HostVow<any>;
 
 /**
  * The function from the host as it will be available in the guest.

packages/eslint-config/eslint-config.cjs

@@ -1,4 +1,16 @@
 /* eslint-env node */
+
+const orchestrationFlowRestrictions = [
+  {
+    selector: "Identifier[name='heapVowE']",
+    message: 'Eventual send is not yet supported within an orchestration flow',
+  },
+  {
+    selector: "Identifier[name='E']",
+    message: 'Eventual send is not yet supported within an orchestration flow',
+  },
+];
+
 module.exports = {
   extends: [
     'airbnb-base',
@@ -95,5 +107,12 @@ module.exports = {
         'no-unused-vars': 'off',
       },
     },
+    {
+      // Orchestration flows
+      files: ['**/*.flows.js'],
+      rules: {
+        'no-restricted-syntax': ['error', ...orchestrationFlowRestrictions],
+      },
+    },
   ],
 };

packages/orchestration/README.md

@@ -3,3 +3,18 @@
 Build feature-rich applications that can orchestrate assets and services across the interchain.
 
 Usage examples can be found under [src/examples](https://github.com/Agoric/agoric-sdk/tree/master/packages/orchestration/src/examples). They are exported for integration testing with other packages.
+
+## Orchestration flows
+
+Flows to orchestrate are regular Javascript functions but have some constraints to fulfill the requirements of resumability after termination of the enclosing vat. Some requirements for each orchestration flow:
+- must not close over any values that could change between invocations
+- must satisfy the `OrchestrationFlow` interface
+- must be hardened
+- must not use `E()` (eventual send)
+
+The call to `orchestrate` using a flow function in reincarnations of the vat must have the same `durableName` as before. To help enforce these constraints, we recommend:
+
+- keeping flows in a `.flows.js` module
+- importing them all with `import * as flows` to get a single object keyed by the export name
+- using `orchestrateAll` to treat each export name as the `durableName` of the flow
+- adopting `@agoric/eslint-config` that has rules to help detect problems

packages/orchestration/package.json

@@ -92,6 +92,6 @@
     "access": "public"
   },
   "typeCoverage": {
-    "atLeast": 98.09
+    "atLeast": 98.05
   }
 }

packages/orchestration/src/examples/auto-stake-it.contract.js

@@ -17,7 +17,7 @@ import { preparePortfolioHolder } from '../exos/portfolio-holder-kit.js';
  * @import {Remote} from '@agoric/vow';
  * @import {Zone} from '@agoric/zone';
  * @import {GuestInterface} from '@agoric/async-flow';
- * @import {CosmosValidatorAddress, Orchestrator, CosmosInterchainService, Denom, OrchestrationAccount, StakingAccountActions} from '@agoric/orchestration';
+ * @import {CosmosValidatorAddress, Orchestrator, CosmosInterchainService, Denom, OrchestrationAccount, StakingAccountActions, OrchestrationFlow} from '@agoric/orchestration';
  * @import {MakeStakingTap} from './auto-stake-it-tap-kit.js';
  * @import {MakePortfolioHolder} from '../exos/portfolio-holder-kit.js';
  * @import {ChainHub} from '../exos/chain-hub.js';
@@ -35,6 +35,7 @@ import { preparePortfolioHolder } from '../exos/portfolio-holder-kit.js';
  */
 
 /**
+ * @satisfies {OrchestrationFlow}
  * @param {Orchestrator} orch
  * @param {{
  *   makeStakingTap: MakeStakingTap;

packages/orchestration/src/examples/basic-flows.contract.js

@@ -9,7 +9,7 @@ import { preparePortfolioHolder } from '../exos/portfolio-holder-kit.js';
 
 /**
  * @import {Zone} from '@agoric/zone';
- * @import {OrchestrationAccount, Orchestrator} from '@agoric/orchestration';
+ * @import {OrchestrationAccount, OrchestrationFlow, Orchestrator} from '@agoric/orchestration';
  * @import {ResolvedPublicTopic} from '@agoric/zoe/src/contractSupport/topics.js';
  * @import {OrchestrationPowers} from '../utils/start-helper.js';
  * @import {MakePortfolioHolder} from '../exos/portfolio-holder-kit.js';
@@ -20,6 +20,7 @@ import { preparePortfolioHolder } from '../exos/portfolio-holder-kit.js';
  * Create an account on a Cosmos chain and return a continuing offer with
  * invitations makers for Delegate, WithdrawRewards, Transfer, etc.
  *
+ * @satisfies {OrchestrationFlow}
  * @param {Orchestrator} orch
  * @param {undefined} _ctx
  * @param {ZCFSeat} seat
@@ -39,6 +40,7 @@ const makeOrchAccountHandler = async (orch, _ctx, seat, { chainName }) => {
  * Calls to the underlying invitationMakers are proxied through the
  * `MakeInvitation` invitation maker.
  *
+ * @satisfies {OrchestrationFlow}
  * @param {Orchestrator} orch
  * @param {MakePortfolioHolder} makePortfolioHolder
  * @param {ZCFSeat} seat

packages/orchestration/src/examples/sendAnywhere.contract.js

@@ -5,7 +5,7 @@ import { Fail } from '@endo/errors';
 import { E } from '@endo/far';
 import { M } from '@endo/patterns';
 import { withOrchestration } from '../utils/start-helper.js';
-import { orchestrationFns } from './sendAnywhereFlows.js';
+import * as flows from './sendAnywhere.flows.js';
 import { prepareChainHubAdmin } from '../exos/chain-hub-admin.js';
 
 /**
@@ -76,7 +76,7 @@ const contract = async (
   );
 
   // orchestrate uses the names on orchestrationFns to do a "prepare" of the associated behavior
-  const orchFns = orchestrateAll(orchestrationFns, {
+  const orchFns = orchestrateAll(flows, {
     zcf,
     contractState,
     localTransfer: zoeTools.localTransfer,

packages/orchestration/src/examples/sendAnywhere.flows.js

@@ -0,0 +1,59 @@
+import { M, mustMatch } from '@endo/patterns';
+
+/**
+ * @import {GuestOf} from '@agoric/async-flow';
+ * @import {VBankAssetDetail} from '@agoric/vats/tools/board-utils.js';
+ * @import {ZoeTools} from '../utils/zoe-tools.js';
+ * @import {Orchestrator, LocalAccountMethods, OrchestrationAccountI, OrchestrationFlow} from '../types.js';
+ */
+
+const { entries } = Object;
+
+// in guest file (the orchestration functions)
+// the second argument is all the endowments provided
+
+/**
+ * @satisfies {OrchestrationFlow}
+ * @param {Orchestrator} orch
+ * @param {object} ctx
+ * @param {{ account?: OrchestrationAccountI & LocalAccountMethods }} ctx.contractState
+ * @param {GuestOf<ZoeTools['localTransfer']>} ctx.localTransfer
+ * @param {(brand: Brand) => Promise<VBankAssetDetail>} ctx.findBrandInVBank
+ * @param {ZCFSeat} seat
+ * @param {{ chainName: string; destAddr: string }} offerArgs
+ */
+export async function sendIt(
+  orch,
+  { contractState, localTransfer, findBrandInVBank },
+  seat,
+  offerArgs,
+) {
+  mustMatch(offerArgs, harden({ chainName: M.scalar(), destAddr: M.string() }));
+  const { chainName, destAddr } = offerArgs;
+  // NOTE the proposal shape ensures that the `give` is a single asset
+  const { give } = seat.getProposal();
+  const [[_kw, amt]] = entries(give);
+  const { denom } = await findBrandInVBank(amt.brand);
+  const chain = await orch.getChain(chainName);
+
+  if (!contractState.account) {
+    const agoricChain = await orch.getChain('agoric');
+    contractState.account = await agoricChain.makeAccount();
+  }
+
+  const info = await chain.getChainInfo();
+  const { chainId } = info;
+  assert(typeof chainId === 'string', 'bad chainId');
+
+  await localTransfer(seat, contractState.account, give);
+
+  await contractState.account.transfer(
+    { denom, value: amt.value },
+    {
+      value: destAddr,
+      encoding: 'bech32',
+      chainId,
+    },
+  );
+}
+harden(sendIt);

packages/orchestration/src/examples/swapExample.contract.js

@@ -6,7 +6,7 @@ import { withOrchestration } from '../utils/start-helper.js';
 
 /**
  * @import {LocalTransfer} from '../utils/zoe-tools.js';
- * @import {Orchestrator, CosmosValidatorAddress} from '../types.js'
+ * @import {Orchestrator, CosmosValidatorAddress, OrchestrationFlow} from '../types.js'
  * @import {TimerService} from '@agoric/time';
  * @import {LocalChain} from '@agoric/vats/src/localchain.js';
  * @import {Remote} from '@agoric/internal';
@@ -17,6 +17,7 @@ import { withOrchestration } from '../utils/start-helper.js';
  */
 
 /**
+ * @satisfies {OrchestrationFlow}
  * @param {Orchestrator} orch
  * @param {object} ctx
  * @param {LocalTransfer} ctx.localTransfer

packages/orchestration/src/examples/unbondExample.contract.js

@@ -2,7 +2,7 @@ import { M } from '@endo/patterns';
 import { withOrchestration } from '../utils/start-helper.js';
 
 /**
- * @import {Orchestrator, IcaAccount, CosmosValidatorAddress} from '../types.js'
+ * @import {Orchestrator, OrchestrationFlow} from '../types.js'
  * @import {TimerService} from '@agoric/time';
  * @import {LocalChain} from '@agoric/vats/src/localchain.js';
  * @import {NameHub} from '@agoric/vats';
@@ -13,6 +13,7 @@ import { withOrchestration } from '../utils/start-helper.js';
  */
 
 /**
+ * @satisfies {OrchestrationFlow}
  * @param {Orchestrator} orch
  * @param {object} ctx
  * @param {ZCF} ctx.zcf

packages/orchestration/src/facade.js

@@ -11,13 +11,13 @@ import { assertAllDefined } from '@agoric/internal';
  * @import {HostOrchestrator} from './exos/orchestrator.js';
  * @import {Remote} from '@agoric/internal';
  * @import {CosmosInterchainService} from './exos/cosmos-interchain-service.js';
- * @import {Chain, ChainInfo, CosmosChainInfo, IBCConnectionInfo, OrchestrationAccount, Orchestrator} from './types.js';
+ * @import {Chain, ChainInfo, CosmosChainInfo, IBCConnectionInfo, OrchestrationAccount, OrchestrationFlow, Orchestrator} from './types.js';
  */
 
 /**
  * For a given guest passed to orchestrate(), return the host-side form.
  *
- * @template {(orc: Orchestrator, ctx: any, ...args: any[]) => Promise<any>} GF
+ * @template {OrchestrationFlow} GF
  * @typedef {GF extends (
  *   orc: Orchestrator,
  *   ctx: any,
@@ -66,18 +66,13 @@ export const makeOrchestrationFacade = ({
   const { prepareEndowment, asyncFlow, adminAsyncFlow } = asyncFlowTools;
 
   /**
-   * @template GR - return type
    * @template HC - host context
-   * @template {any[]} GA - guest args
+   * @template {OrchestrationFlow<GuestInterface<HC>>} GF guest fn
    * @param {string} durableName - the orchestration flow identity in the zone
    *   (to resume across upgrades)
    * @param {HC} hostCtx - values to pass through the async flow membrane
-   * @param {(
-   *   guestOrc: Orchestrator,
-   *   guestCtx: GuestInterface<HC>,
-   *   ...args: GA
-   * ) => Promise<GR>} guestFn
-   * @returns {(...args: HostArgs<GA>) => Vow<GR>}
+   * @param {GF} guestFn
+   * @returns {HostForGuest<GF>}
    */
   const orchestrate = (durableName, hostCtx, guestFn) => {
     const subZone = zone.subZone(durableName);
@@ -92,7 +87,7 @@ export const makeOrchestrationFacade = ({
     const hostFn = asyncFlow(subZone, 'asyncFlow', guestFn);
 
     // cast because return could be arbitrary subtype
-    const orcFn = /** @type {(...args: HostArgs<GA>) => Vow<GR>} */ (
+    const orcFn = /** @type {HostForGuest<GF>} */ (
       (...args) => hostFn(wrappedOrc, wrappedCtx, ...args)
     );
 
@@ -106,11 +101,7 @@ export const makeOrchestrationFacade = ({
    *
    * @template HC - host context
    * @template {{
-   *   [durableName: string]: (
-   *     orc: Orchestrator,
-   *     ctx: GuestInterface<HC>,
-   *     ...args: any[]
-   *   ) => Promise<any>;
+   *   [durableName: string]: OrchestrationFlow<GuestInterface<HC>>;
    * }} GFM
    *   guest fn map
    * @param {GFM} guestFns

packages/orchestration/src/orchestration-api.ts

@@ -9,6 +9,7 @@ import type { CurrentWalletRecord } from '@agoric/smart-wallet/src/smartWallet.j
 import type { Timestamp } from '@agoric/time';
 import type { LocalChainAccount } from '@agoric/vats/src/localchain.js';
 import type { ResolvedPublicTopic } from '@agoric/zoe/src/contractSupport/topics.js';
+import type { Passable } from '@endo/marshal';
 import type {
   ChainInfo,
   CosmosChainAccountMethods,
@@ -192,6 +193,10 @@ export interface OrchestrationAccountI {
   getPublicTopics: () => Promise<Record<string, ResolvedPublicTopic<unknown>>>;
 }
 
+export interface OrchestrationFlow<CT = unknown> {
+  (orc: Orchestrator, ctx: CT, ...args: Passable[]): Promise<unknown>;
+}
+
 /**
  * Internal structure for TransferMsgs.
  * The type must be able to express transfers across different chains and transports.

packages/orchestration/test/examples/bad.flows.js

@@ -0,0 +1,25 @@
+/**
+ * @file Module with linting errors, to verify the linting config detects them.
+ *   This assumes `reportUnusedDisableDirectives` is enabled in the local
+ *   config.
+ */
+
+// TODO error on exports that:
+// - aren't hardened (probably a new rule in @endo/eslint-plugin )
+// - don't satisfy orchestration flow type
+
+// eslint-disable-next-line no-restricted-syntax -- intentional for test
+import { E } from '@endo/far';
+
+export function notFlow() {
+  console.log('This function is not a flow');
+}
+
+export async function notHardened() {
+  console.log('This function is the most minimal flow, but it’s not hardened');
+}
+
+export async function usesE(orch, { someEref }) {
+  // eslint-disable-next-line no-restricted-syntax -- intentional for test
+  await E(someEref).foo();
+}